Thermodynamic simulation of phase equlibria of oxide systems containing rare-earth metals. Report 3. Phase diagrams of oxide systems with Ce2O3 and CeO2

Abstract

Binary and ternary oxide systems, containing cerium oxides (III and IV) as independent components have been researched. The forms of binary and ternary phase diagrams, conjugated with the region of iron-based liquid metal phase existence were established. The calculation of liquidus curve coordinates for binary phase diagrams of Ce2O3–MgO, CeO2–MgO, Ce2O3–СaO, CeO2–СaO, Ce2O3–SiO2, CeO2–SiO2, Ce2O3–Al2O3, CeO2–Al2O3 systems was carried out using selected energy parameters of theory of subregular ionic solutions. Thermodynamic dependencies of equilibrium constants of reactions of cerium aluminates (Ce2O3·Al2O3, Ce2O3·11Al2O3) and silicates (SiO2, 7Ce2O3·9SiO2, Ce2O3·2SiO2) formation from ionic melt components were defined. Phase diagrams of ternary oxide systems FeO–CeO2–SiO2, FeO–Ce2O3–SiO2 were created for the first time on the basis of thermodynamic data on oxide compounds, melting heat of oxides forming the systems researched, values of energy parameters of theory of subregular ionic solutions. The calculation of liquidus curve coordinates for ternary systems FeO FeO–Ce2O3–CeO2, FeO–Ce2O3–CaO, FeO–CeO2–CaO, CeO2–Ce2O3–CaO, FeO–Ce2O3–MgO, FeO–CeO2–MgO, CeO2–Ce2O3–MgO is based on the theory of ideal ionic solutions. Phase diagrams of FeO–Ce2O3, Ce2O3–CeO2, FeO–Ce2O3–CeO2, FeO–Ce2O3–Al2O3 systems were redetermined and re-calculated.